Something I figured out that I am posting to help others.
To install Windows 10 Pro on PowerEdge R240 with a PERC S140
1. On the R240 server set to BIOS not UEFI, You can do this in Lifecycle Controller.
On another PC:
2. Download the Windows 64 bit PERC S140 drivers from Dell. I found these on the R240 downloads page. Here is the file name: "SAS_RAID_DRIVER_WS2016_S140_5.4.1-0001_A04_ZPE.exe" NOTE: These are Windows Server 2016 64 bit drivers, but they work for Windows 10 because Windows 2016 Server uses the same Kernel as Windows 10 Pro.
3. Run the executable to expand the driver files. Copy the driver files to a CD.
Back on the R240 Server:
4. Plug a portable USB DVD/CD drive into an available USB slot on the server. Or you can put this in later.
5. Put the Windows 10 install DVD into the built in DVD/CD drive.
6. Boot into the Windows 10 install disk.
7. Start the Windows install.
8. When Windows prompts you for media that is missing, because it can't find the hard drives, because it can't find the RAID controller drivers, point to the drivers on the portable DVD/CD drive.
Thanks! You just solved the issue I was dealing with for the past 2 hours!
I did something different and put those S140 drivers onto the USB bootable drive I had to install Windows. Then I manually selected the driver to view my RAID1 drive I had created.
I also had to install a few other of the Server 2016 drivers on the Windows 10 box, from the Dell web site, but eventually, I got all of the drivers in Device Manager to install - NO YELLOW exclamation marks. 😉